Caffeine Overdose Symptoms: Signs, Cases, Prevention


Top 10 Caffeine Overdose Symptoms

Here are the usual symptoms in order from the first ones to be experienced to the more severe, later stage consequences.

  1. Jitters, Restlessness, and Nervousness
  2. Increased heartbeat
  3. Nausea
  4. Anxiety
  5. Heart palpitations (cardiac arrhythmia)
  6. Insomnia
  7. Sweating
  8. Dizziness
  9. Vomiting
  10. Cardiac arrest

There can be many common symptoms that indicate too much caffeine consumption, but these are the most prevalent.

These symptoms should be recognized and further caffeine intake should be stopped to avoid more serious and even life-threatening symptoms.

Ingesting massive doses of caffeine all at once is particularly dangerous as it doesn’t give your body time to react. Overdose symptoms serve as an early warning system.

Caffeine’s major effects are experienced for at least 4 hours.

  • This is longer for those sensitive to caffeine.
  • This is longer with extremely large doses.
  • This is based on the half-life of caffeine which is 4-6 hours.

It’s hard to pinpoint an amount of caffeine that will cause these caffeine overdose symptoms as people have different tolerance levels.

Are You Addicted to Caffeine?

You may want to consider quitting. A detox program like Wean Caffeine is scientifically designed to help you quit caffeine gradually and safely. This prevents the horrible withdrawal most people experience when quitting.

Prevention: Maximum Daily Intake

You can prevent caffeine overdose by adhering to the recommended safe dosage guidelines.

Generally, a dose between 250-500mg (check caffeine amounts here) could produce some of the above mild to moderate symptoms, especially in those with no tolerance of high caffeine sensitivity.

Those with a caffeine allergy or sensitivity could have severe symptoms even after a very small dose.

Click here to find out how much of a popular drink would it take for you to overdose.

DSM-5 Criteria

Insomnia is a common symptom of too much caffeine

Caffeine Intoxication is now included in the DSM-5 physicians manual.

The official diagnosis can be made when any 5 of the following symptoms are present: restlessness, nervousness, excitement, insomnia, flushed face, diuresis (you keep passing urine), gastrointestinal disturbance (upset tummy, diarrhea), muscle twitching, rambling flow of thought and speech, tachycardia or cardiac arrhythmia, periods of inexhaustibility, or psychomotor agitation.

The DSM-5 now also lists Caffeine Withdrawal as a mental disorder. Sufferers can experience withdrawal symptoms when ceasing caffeine intake.

Caffeine Addiction as a disorder was rejected from the next version of the manual.

Reducing the Impact of Caffeine

There is some research indicating products that contain rutaecarpine can actually reduce the impact of caffeine’s side effects. They do this by assisting with caffeine metabolism*. Learn more here.

Caffeine Overdose Documented Cases

Caffeine overdose does happen and has been documented. Here are some of the more recent cases resulting in death or hospitalization;

  • 19-year-old James Stone dies after taking 25 to 30 No Doz pills in 2007. (at least 2.5 grams of caffeine)
  • 40 Seagulls die from caffeine overdose in Canada this year from eating used coffee grinds.
  • 17-year-old Jasmine Willis, a Durham, UK waitress overdosed by drinking 7 double espressos in 2007. She was taken to the hospital but recovered soon after. (that’s roughly 1.078 grams)
  • In the late 1990’s an Australian woman, with a heart condition died after consuming a guarana based shot from her local health food store. This product is no longer on the market. (10g/liter, ok that’s just nuts!)
  • 2010 a 23-year-old British man from Mansfield, England died after taking to 2 spoonfuls of pure caffeine powder washed down by an energy drink at a party. His death was ruled accidental.
  • 2011 Fourteen-year-old Anais Fournier, died after she consumed two 24 ounce Monsters (480mg of caffeine) in a 24 hour period. The cause of death was a heart arrhythmia due to caffeine toxicity.  There seem to be some conflicting stories as to how much she really consumed and this seems true since 480mg in a 24 hour period isn’t a toxic amount. Update October 2012: Her parents are suing Monster Energy for wrongful death although the girl did have a known pre-existing heart condition.
  • 2012 The FDA is investigating Monster Energy since the energy drink has been linked to five deaths over the past year.
  • 2013: According to the Substance Abuse and Mental Health Services Administration, energy drink-related ER visits have doubled in the last 4 years, however, 42% of these visits involved caffeine in combination with other drugs such as alcohol or other narcotics. src.
  • 2013 a New Zealand woman died from cardiac arrhythmia associated with her 10 liter/day Coca-Cola habit. She also smoked 30 cigarettes a day and barely ate. Caffeine was a contributing factor, but the 900-1000mg daily dose wasn’t the only factor. src.
  • 2013 A mother is suing Monster Energy for the death of her 19-year-old son, Alex Morris, after he died of cardiac arrest. She claims that he drank two 16 ounce Monsters the day before his death and at least two a day for the 3 years preceding his death. A California Coroner’s office reported that he died from cardiomyopathy and cardiac arrhythmia.
  • October 2013: John Jackson from the UK dies after eating a whole tin of HERO Energy Mints. Each tin contains 12 mints, so he consumed 984mg of caffeine. He also had cirrhosis of the liver, which prevented him from processing the caffeine properly allowing it to build up in his bloodstream to lethal levels. (src.)
  • March 2014: A 14-year-old boy from Norway was hospitalized with kidney failure after drinking 4 liters of a caffeine-laced energy drink while gaming for 16 hours straight. This would be around 1,280mg of caffeine if he was consuming a “Red Bull” like energy drink. (src.)
  • September 2014: A Tennessee man was taken to the hospital after consuming 20 caffeine pills to “test the limits of his body” according to what the man told the paramedics. He ingested 4000 mg of caffeine at once. src.

Caffeine Overdose Facts

too-much-caffeineLuckily for us, we have mechanisms built into the human body that let us know we’ve had enough of something.

This is true with caffeine overdose. Well before we are at a toxic level we experience side effects that prevent us from consuming more, i.e. nausea and vomiting.

This means that before the 149 or so cans of Red Bull that it would take to kill an average adult male, vomiting would most certainly happen.

For most, that would happen after about can number 5!

It’s important to note, however, that caffeine is a drug and should be respected and not abused. Since some people have extremely low tolerance to caffeine, they could  – in theory – overdose quite easily.

How to Know If You’ve Overdosed

Most people feel the “jitters” first – a sensation of tremors or shaking.

This is your signal to stop consuming caffeine for the day.

You should also be aware of the caffeine levels in what you are drinking. Please consult the caffeine database. Some of the caffeine amounts will surprise you.

If you are finding you are often tired after consuming caffeine this is a sign that you need to change your long-term habits and could indicate adrenal fatigue.

The bottom line is to be aware of what you are consuming.

How common is caffeine overdose?

With the plethora of caffeinated products in the marketplace, one could assume that overdosing on caffeine is quite common.

If we look at the statistics from The American Association of Poison Control Centers we find that, while it does exist, it isn’t as common as we might think.

In fact, overdosing on Tylenol is a lot more common than overdosing on caffeine.

Since caffeine is consumed so widely, there are a lot of half-truths, hearsay, urban legends, media hype, and even fiction.

It’s good to take an honest look at the subject and try to put all of the information into perspective. We can then determine if caffeine should be in the same category as other drug overdoses are.

Get Help Quitting Caffeine

Reduce your caffeine intake without pain and discomfort.

See our new 10-step plan
  • Lance

    Just the other day I had around 500 to 1000 mg of caffeine. I’m a dummy! I had a cold sweat and at first shanking uncontrollably i took my heart rate and I was at 95 beats per minute I was sitting in a chair… now I am above average in health Im a 19 year old male that was around 145lb when I first started drinking my energy drinks after 2 days of not very much sleep I have lost 10 lbs and still currently have an elevated heart rate… listen DONT TAKE A LOT OF CAFFEINE I AM STILL RECOVERING FROM MY EXPERIMENT AND NOW MORE THEN EVER DONT WANT PEOPLE TO DO WHAT I HAVE DONE… PLEASE BE SMART ABOUT YOUR USE! God knows I wasn’t and now I’ve been struggling just to stay out of the hospital be carful

  • Shane

    I have done an experiment to see if you can Really overdose on caffeine or if you just get jittery, so far I’ve drank 4 pots of Maxwell house Coffee completely black and nothing but an amazing rush of energy! Some people may be sensitive to caffeine and should know their limits, but this goes to show that everyone’s body is different and it doesn’t happen to everybody!

  • Wesley Loggins

    Yesterday I had a caffenie overdose and went into Cardiac arrest the first thing they asked me was if I had any cocaine or meth in my system and they where insistant on it untill i took a drug test and came up clean and now even after the heartattack they are sending ne back to the third shift which was the reason I consumed the caffeine in the first place

  • Badr Najah

    I agree with this article.

    I believe most deaths are because of underlying heart condition. It also varies significantly from one person to another.

    The seagulls part was really funny to me.

  • Tamo

    I want to know how many monster energy drinks is too much

  • Lengo

    Another symptom of overdose: If you’re around me and are talking, talking, talking and won’t SHUT UP, I’ll punch in the mouth! Add broken jaw to the list of symptoms of caffeine overdose!

  • Rob

    I’m 5’11 n 175lbs. I just consumed 1200 milligrams of caffeine which breaks down to a little over 1 gram. We shall see what happens… Figure if i start getting to the more serious symptoms I can always go make myself throw up. I’m from Milwaukee, WI so watch the news n see if there’s any reported cases of an overdose from a 28yr old male.

  • Lock

    3 days ago I consumed a total of 8500mg of caffeine by swallowing 85 no-doz tablets. The reasons are irrelevant but some curiosity was underlying as to wether or not I would go into cardiac arrest or worse. After an hour my resting bpm reached 140-150 and after 2 hours I started throwing up and I didn’t stop throwing up for 13-15 hours. Went to the hospital and my bpm had dropped to 100 and after a day of tests (no I didn’t tell them about the caffeine) they said I was fine and sent me home to rest up. The only thing that happened was I couldn’t eat properly and I didn’t sleep for 6 days but felt as awake as ever before. I also lost quite a bit of weight as you could imagine 13-15 hours of vomiting followed by almost 6 days without eating would do to you. So all in all I’d say the only way caffeine is dangerous is if you have an underlying heart condition. Take it from the guy that consumed 8.5g of pure caffeine and is writing this comment.

  • Emily

    The seagull thing is not very mature. It is not funny at all. No one feeds these animals, and if humans are disgusting enough to leave it out, they will obviously mistake it for food.
    article is good, but redundant.

  • Rebecca

    I agree with Emily. Only a rather emotionally immature individual would find poisoning animals “just funny”. Did you pull the wings off flies when you were young and find that “just funny” too? Enjoying cruelty to animals is a classic sign of anti-social behavior that is the precursor to later violence. You – as well as those who agreed with you – probably need to stay away from caffeine and all other stimulants (and depressants).

  • nik

    i used to drink a litre of energy drink a day
    and had done for years. but then i had one litre and two no dose plus and almost passed out while driving.
    i had no idea why and eventually pin pointed it down to caffine.
    i got heart scans stress test the lot and the docs couldnt figure out why i got it, they said im perfectly healthy.
    every time i have caffine now i get it. added with rappid heart beat irregular breathing and the worst case pins and needles in both arms head and tongue and dissy as hell. it feels like im going to die!!
    i just put it down to caffine gives me anxiety and steer clear of it. . i would love to know why i was fine all those years and it just hit me one day.

  • Flabbabotty

    Seagulls are evil little fiends, I wouldn’t like to see them poisoned though. I’d prefer them shot, plucked and roasted like chestnuts on an open fire.
    Caffeine is a drug which has a lower LD-50 than ecstasy, but both are enjoyable as long as you don’t take 40-80 pills, these sort of people are why it’s necessary to have “may contain nuts” printed in the allergy advice info on the back of a pack of peanuts.
    Darwin said it best when he said “If ya gotta be dumb, you gotta be tough”
    You already wrecked drugs for everyone, don’t take away my Monster and coffee………….heathens

  • tamza

    I accidently overdosed on caffine after sniffing a rather large amount, I spent 15 hours throwing up and have had a very very upset stomouch after not being able to eat or drink, but I am also getting very sharp stabbing pains on and off above my bladder n they get stronger when I go to the toilet, is this normal? n is it to do with the caffine ect?

  • Tris

    Wow, this really opened my eyes, i took 5 200mg caffine pills the other day, to get a buzz (being dumb) and i got EXTREMELY sick. So now i know i basicly attemted suiside. Great. Lol. But seriously.

  • NATE

    This site has some super good info on caf. and related products. Too bad it has no moderators as some of this stuff is just crap. Simon-39 Monsters, 24 Panadol Extra and 20 cups of tea a day. Your liver would shut down long before you reached 24 doses of acetaminophen in a day. Dylan- 8oz. of 5150? Who could be that stupid? Lock-85 No-Doz? how about No-Way. Tamza- Referring to an overdose as accidental after snorting Caffeine?? If you are snorting it accident is off the table. Try stupidly overdosing, it would be more accurate. As for all the seagull boohooing, really? I don’t advocate cruelty to animals but they subsist on garbage so coffee grounds is not the biggest of their worries I am sure, let it go. And I culled this from the first 30 or so comments of the over 152 posted. This kind of stuff undermines the credibility of the good info available on this site. Just sayin.

  • ted

    This site is moderated, and we encourage different view points as well as people sharing their experiences. What’s in the comments doesn’t change what’s in the content of the article. Whether or not you agree or disagree with comments, think they are BS, or whatever that is your opinion. We allowed you to share, just like we will continue to allow others to share in the comments.

  • Nathan

    I probably had caffeine overdose once. I took a couple of caffeine pills, ground them up, mixed them with red bull and mixed that with Coke. (Yes… I know, stupid). I got really nauseated, I was seeing spots, palpatations (felt like I was going to have a heart attack or something), and I was moving a mile a minute. In fact, the only way my nausea subsided was when I was working my ass off… If I would have slowed down the pace, I would have gotten sick.

    After the caffeine wore off, I had the similar symptoms of a hangover (headache, stomach ache, heart burn, fatigue). And afterwards, caffeine pills would cause me stomach aches. All because I was falling asleep at the job.


  • Ravo

    Everyone is different: I get jittery, slight nausea, and loss of concentration from only a couple of espressos. It’s really not a nice feeling!

  • chriz

    I had been taking energy drinks to go to the gym and after my 9 to 10 month of doing it day after day, I started getting this dizziness and heache. I realize its to much caffeine. I stopped for like 6 months and still had that dizziness and heaches. After the 6 monts i started being the same. mild dizzinness and heaches. then i went back to my energy drinks and the same thing is starting to happend. as i write i have this dizziness and heache. Am stopping today and will not be drinking any more caffeine. This is some serious illness.

  • Deborah Carroll

    the problem with the dizziness is that the energy drinks have aspartame in them (splenda, which is a fake sugar) and this severely weakens the equilibrium dizziness center in the brain, which shows in the left iris patterns btw in iridology charts.

    anyway that is the cause of the dizziness and the remedy is blue cohosh which is an herb…also unheated honey for natural insulin

    sorry you had to suffer


    also most coffee is loaded with pesticides
    organic is best

Last Modified: November 13, 2017


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